Bridge Server Monitoring

To determine if the Bridge Server is running, use either of the following:

• Ingres Visual Manager
• The iinamu utility's show bridge command

Stop the Bridge Server

You can use either the ingstop command or Ingres Visual Manager to stop the Bridge Server.

To stop the Bridge Server using ingstop

Issue the following command at the operating system prompt:

ingstop –iigcb

How a Connection Is Established Through Bridge

When an application on one type of local area network attempts to establish a connection to a server on a different type of network, the following sequence of events establishes the connection:

• The application gets the local Name Server (iigcn) listen address and connects to the local Name Server to request remote access.
• The local Name Server passes the listen address of the local Communications Server (iigcc) and the listen address of the remote Bridge Server (iigcb) back to the application. (The local Name Server (iigcn) stored the remote Bridge Server's listen address when you defined a vnode for the remote node on which the Bridge Server is running.)
• The application connects to the local Communication Server, passing it the remote Bridge Server's listen address as part of the remote access request.
• The local Communications Server connects to the remote Bridge Server. The remote Bridge Server gets the connection data entries from the Name Server on that instance and re-directs the connection to the Communications Server (iigcc) on the target database's network using the connection data that it received from the Name Server.
• The Communications Server on the target database's network (a different network than that of the requesting application) finds the listen address of the Name Server on that network's installation. The Communications Server requests connection information from the Name Server by passing the name of the database for which the connection is requested.
• The Name Server returns the listen address of a DBMS Server on that instance that is capable of servicing a request for connection to the target database.
• The Communications Server (iigcc) connects to the DBMS Server on the remote instance.

When these steps are completed, a virtual connection has been established between the application and the DBMS Server through the Bridge Server.

Bridge Troubleshooting

Most problems with Ingres Bridge are related to one of the following situations:

• Network or protocol not properly installed
• The Name Server (iigcn), Communications Server (iigcc), or Bridge Server (iigcb) process not running
• Incorrect netutil entries
• Port connection problems

To determine the origin of a problem, begin by examining the Ingres error file, errlog.log. The Bridge Server's startup and shutdown messages and Ingres Bridge error messages are logged to this file. The error log is maintained in the following file:

Windows:

%II_SYSTEM%\INGRES\FILES\ERRLOG.LOG

UNIX:

$II_SYSTEM/ingres/files/errlog.log

VMS:

II_SYSTEM:[INGRES.FILES]ERRLOG.LOG

For additional information on problems related to the Bridge Server process, see the chapter "Troubleshooting Connectivity."